Previous research showed that people can recall the first verse of a song they like, but after the chorus stumble over the lyrics. At this point the song becomes incomplete — a conflict without closure, Hyman said. "You get to the chorus, and then it's looping right there, and you're kind of doomed at that point," he said.

The study found that songs typically intrude during tasks that are either too difficult, which causes the mind to wander, or too easy, which creates a mental opening for repetitive thoughts. The trick to flushing out an earworm, Hyman said, is to find a task that is engaging and that requires the auditory and verbal components of your working memory — like reading a good book or watching a favorite show.

A Mediterranean diet, even drenched in olive oil and studded with nuts, beats a low-fat diet hands-down in preventing strokes and heart attacks in healthy older people at high risk of cardiovascular disease, according to new research.

The latest smack-down in the diet wars appears to deal a knock-out blow to the notion that high-fat olive oil and tree nuts — walnuts, almonds and hazelnuts — are a no-no for those wishing to improve their health. On the contrary, Spanish researchers concluded that the consumption of extra-virgin olive oil and nuts "were probably responsible for most of the observed benefits" attained by those in the two study groups on a Mediterranean diet.

The findings, released by the New England Journal of Medicine, also add to mounting evidence contradicting a long-held tenet of dieting to improve health: that all calories are equal. A Mediterranean diet is rich in fatty fish, fruits, vegetables and fatty acids, and almost entirely without red meat.

Pregnant women who received the flu vaccine during the 2009 influenza pandemic lowered their risk of delivering premature babies, a new study found.

Typically, flu vaccination rates among pregnant women have hovered around 13 to 18 percent nationally. But a push by health officials during the 2009 season drove vaccination rates for the H1N1 vaccine up to about 45 percent in the United States, where they have since remained.

The study, published in the journal Clinical Infectious Diseases, found that the infants born to vaccinated mothers had a 37 percent lower likelihood of being premature, and they also weighed more at birth than babies born to unvaccinated women.

"Our thinking is that by preventing flu infection, we are reducing the likelihood of inflammation in pregnant women and therefore having a protective effect against preterm birth," said Dr. Saad Omer of the Rollins School of Public Health at Emory University, the senior author of the study..